Dubois' dashboard reveals a picture of The Beatles in a scene from "A Hard Day's Night" which did not begin filming until March 1964, one month after The Beatles' first appearance on the Sullivan show.
In the record store, many "Meet The Beatles" copies are visible with "Meet The" in light blue. In 1964, the album had those words in brown. It wasn't until years later that the light blue version was released.
At the end of the "Ed Sullivan Show" broadcast in I WANNA HOLD YOUR HAND, the house orchestra is heard playing the "Toast of the Town" theme tune, which had been abandoned by Sullivan's production crew several years prior to the 1963-64 television season.
When Tony Smerko catches Larry DuBois selling fragments of Beatles bed sheets in a building entryway, he knocks the stack out of Larry's hands and they are shown scattered around their feet on the floor. Tony goes on to berate Larry for a moment in a shot from the waist up, with neither of them bending down to pick up the sheet fragments, but when they proceed to walk off together, the stack of sheet fragments is gone.
When Tony and Janis are up on the roof of the CBS studio, there's a green Art Deco building with a clock and the word "Eastern" in the background. This is the Eastern Columbia building, a downtown Los Angeles landmark.
The film is set in New York City during February, yet in several scenes outside the hotel, there are trees with green leaves. At this time of year in NYC, these trees would actually have totally bare branches with no leaves.
During the climactic Sullivan appearance, the Beatles start their set with "She Loves You". In reality, "She Loves You" was the third song in the set, following "All My Loving" and "Til There Was You".
In his pre-titles address to the CBS pages, Will Jordan's version of Ed Sullivan says that he and his wife Sylvia had seen The Beatles perform in England the previous year. In fact, the real-life Sullivan had booked The Beatles for his show based on the reaction they drew from fans at London's Heathrow Airport, which delayed the Sullivans' own flight to New York. The first time Sullivan saw The Beatles perform was on a film that had been aired on CBS Evening News with Walter Cronkite on December 10, 1963, weeks after the booking had been made.
Among the products advertised during the Ed Sullivan broadcast in I WANNA HOLD YOUR HAND is Brylcreem. In fact, Brylcreem was not advertised on the actual Ed Sullivan broadcast of February 9, 1964, and the placement of the commercial in the movie was probably director Robert Zemeckis' personal joke relating to the Beatles' hair style - which certainly didn't require the use of Brylcreem.
At the end of the Ed Sullivan broadcast in I WANNA HOLD YOUR HAND, Will Jordan as Sullivan announces that The Beatles will return the following week for a broadcast co-starring the Budapest Ballerinas and Will Jordan himself. The actual announced co-star of that broadcast was, in fact, Mitzi Gaynor, and Jordan never appeared on an "Ed Sullivan Show" on which The Beatles also performed in person. However, one notable impressionist did appear on a Sullivan broadcast alongside The Beatles - Frank Gorshin, on the real-life broadcast of February 9, 1964, that was depicted in the film.
The goof item below may give away important plot points.
While the lead characters encounter various situations which will cause them to be late for the start of the Ed Sullivan Show featuring the Beatles, it is mentioned several times that the Beatles, being the main attraction, will not perform until the end of the show. The Beatles, in reality, performed twice on their initial Ed Sullivan appearance, one set at the beginning of the show and a second set at the end.